A Passive Keyless Entry (PKE) system is a system that provides a user access to a protected area (e.g., a protected object such as a house, office building or car) without the need of actively using a key or key fob. The only requirement is that the user has the key fob with him or her and that he or she is in the proximity of the protected area. It may be desirable to improve the security of existing PKE systems.